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Tiger trout unleashed to topple invasive tui chub population

An Oregon lake is in huge trouble, and the ferocious tiger trout may be its last hope.

When it comes to invasive species, Oregon wildlife officials are not messing around. According to a report from Discovery News, biologists from the Oregon Department of Fish and Wildlife have announced a plan to unleash 25,000 voracious tiger trout into Diamond Lake to eradicate the invasive tui chub.

The tui chub has been responsible for the all-out destruction of Diamond Lake’s ecosystem numerous times in the past. Just nine years ago, officials shocked the entire lake with a deadly chemical in attempt to repopulate it with only native species, but the tui chub remains a resilient invader that seems almost impossible to eradicate.

Biologists think the tui chub was released into Diamond Lake by fishermen using them as bait. The fish were prolific spawners, overwhelming the native food chains and pushing out weaker native species. Invasive species are often so difficult to control because they lack natural predators in their new habitat. Tens of thousands of the tiny chubs squeezed out local species as they ran through food supplies and all but ruined the ecosystem in Diamond Lake.

In 2006, Oregon wildlife officials decided that the only way to solve the tui chub problem would be to kill everything in the lake. They dumped massive amounts of the chemical rotenone into the water, hoping that once the water was devoid of life, they could begin to reintroduce native species without the addition of the unwanted tui chub.

But the little chub persisted, and now officials are calling in the big guns. They will release 25,000 tiger trout, a hybrid species that has a voracious appetite for fish.

The most recent discovery of a single tui chub in the lake led to the daring move. While 25,000 tiger trout could have their own effect on the lake’s ecosystem, their effects would likely not be permanent. Since they are hybrids, they can’t reproduce with one another; their numbers will taper off after the first generation of inhabitants.

According to Oregon wildlife biologist Greg Huchko, “I’m hoping it was the only tui chub, but I’m operating on the assumption that it wasn’t.”

A press release from the Oregon Department of Fish and Wildlife describing a recent tui chub invasion can be found here.